Long-term marketable yields of horticultural crops in southern Ontario in relation to seasonal climate

2005 ◽  
Vol 85 (2) ◽  
pp. 431-438 ◽  
Author(s):  
Alan McKeown ◽  
Jon Warland ◽  
Mary Ruth McDonald

In Ontario, Canada, marketable yields of certain annual horticultural crops increased steadily from 1940 to the mid-1980s, then dramatically decreased and became highly variable. This was not seen in field crops such as soybean and corn. Standard climatological variables showed little correlation with yields of vegetable crops such as tomatoes, cabbage, cauliflower, onions and rutabagas. The number of hot days (defined as days with maximum temperature greater than 30°C) and number of days with precipitation were better correlated with cool-season vegetable crop yield. With these climate measures we identified a period of milder growing season climate, from 1961 to 1986, and there was a greater frequency of hot days before and after this period. This analysis shows that horticultural crops are more sensitive to specific synoptic events, such as periods of hot days, than to overall growing season climate, and their yields may provide an indicator of a changing climate. Key words: Horticultural yields, historical climate, weather

HortScience ◽  
2013 ◽  
Vol 48 (7) ◽  
pp. 863-869 ◽  
Author(s):  
Michael T. Tesfaendrias ◽  
Mary Ruth McDonald ◽  
Jon Warland

The relationship between long-term weather and yield of 11 horticultural crops and one field crop in Wisconsin was determined for a 55-year period (1950–2005). The relationships among weather parameters and yield in Wisconsin were also compared with associations between weather and yields in Ontario, Canada, from a previous study. The number of days in a growing season with maximum temperatures 30 °C or greater (hot days) was negatively correlated with yields of beet for canning (r2 = 0.15), green pea (r2 = 0.16), onion (r2 = 0.08), and sweet corn for processing (r2 = 0.16) in Wisconsin. Hot days were also negatively correlated with yield of green pea (r2 = 0.16) in Ontario, Canada. Growing season precipitation in Wisconsin was positively correlated with yields of beet for canning (r2 = 0.18) and green pea (r2 = 0.09). An increase in yields of beet for canning in Wisconsin and green pea from Ontario was also observed with an increase in number of days with rainfall during the growing season (r2 = 0.12 and 0.15, respectively). Monthly minimum and maximum temperatures and hot days had an effect on vegetable yields in Wisconsin. A high number of days with precipitation in May and July was associated with yields of most vegetables and grain corn in Wisconsin. These results indicated the importance of the total and frequency of seasonal precipitation and the negative effect of exposure of crops to extreme temperatures on yields of vegetable crops.


2006 ◽  
Vol 84 (7) ◽  
pp. 1031-1036 ◽  
Author(s):  
A.W. McKeown ◽  
J. Warland ◽  
M.R. McDonald

It is accepted knowledge that weather affects yields and climate dictates which crops will grow in a region. Specific weather events, such as drought or hail, that affect yield or quality, are known, as are the general climatic conditions required for groups of crops such as cool season vegetables or tropical crops. However, more precise information on how changes in long-term weather and climate influence the yield of specific vegetable crops is not available. Studies of yield over long periods have the advantage of reflecting the combined effects of numerous environmental variables, including climate effects on physiological stress, pests, and diseases. A study of yields of cool season vegetable crops in Ontario revealed that a decrease in yields is related to an increase in the number of hot days with maximum temperatures over 30 °C. A clear warming trend in Ontario weather is evident, beginning in the mid-1980s, with increasing numbers of hot days and more variable temperatures from year to year. Furthermore, yields of cole crops declined by 10% for every 10 d with temperatures >30 °C in the growing season. Several other studies on agronomic crops worldwide show reductions in yield resulting from warmer temperatures. For example, in a study of rice in the Philippines, yield was reduced by 10% for every 1 °C increase in minimum temperature during the dry season. Methods for evaluating long-term climate effects on crop yield are discussed.


2008 ◽  
Vol 18 (3-4) ◽  
pp. 206 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
L. JAUHIAINEN ◽  
K. HAKALA

As the northern hemisphere will experience the greatest increases in temperature and indications of climatic change are already visible in the north (in the 2000s average temperatures exceeded the long-term mean), we sought to establish if there are already signs of increased variability in yield and quality of the major field crops grown under the northernmost European growing conditions: spring and winter cereals (barley Hordeum vulgare L., oat Avena sativa L., wheat Triticum aestivum L., rye Secale cereale L.), spring rapeseed (turnip rape Brassica rapa L., oilseed rape B. napus L.), pea (Pisum sativum L.) and potato (Solanum tuberosum L.). We used long-term yield datasets of FAO for Finland (1960s to date) and MTT Agrifood Research Finland (MTT) Official Variety Trial datasets on yield and quality of major field crops in Finland since the 1970s. Yield variability was exceptionally high in the 1980s and 1990s, but previously and subsequently national yields were clearly more stable. No progressive increase in yield variability was recorded. No marked and systematic changes in variability of quality traits were recorded, except for rapeseed, which exhibited reduced variability in seed chlorophyll content. This may at least partly attribute to the differences in intensity of input use and thereby responsiveness of the crops before and after 1980 and 1990 decades. We also noted that in the 2000s average temperatures were higher than in earlier decades and this was the case for all months of the growing season except June, which represents, however, the most critical phase for yield determination in most of the field crops in Finland. Also in the 2000s precipitation increased in the first three months of the growing season and thereafter decreased, but without signs of significantly increased numbers of heavy showers (extreme rain events). Hence, in general constant, increased average temperatures during the growing seasons of the 2000s were identified, but with reduced yield variability, which was partly attributable to the diminished use of inputs, especially fertilisers.;


1992 ◽  
Vol 2 (1) ◽  
pp. 89-91
Author(s):  
Joseph F. Guenthner

Vegetable producers and marketers make business decisions based on supply estimates. The U.S. Dept. of Agriculture provides estimates of planting intentions for field crops but not for most vegetable crops. This study developed models that can be used to forecast vegetable crop plantings. Multiple linear regression analysis was used to determine the factors that influence plantings of potatoes and onions. Field crop planting intentions, industry structure, lagged values of plantings, prices received, price volatility, and the price of sugar beets were found to be significant factors. The models and/or methods used in this study should be useful to those interested in forecasting vegetable plantings.


2021 ◽  
Vol 117 (9/10) ◽  
Author(s):  
Beatrice Conradie ◽  
Jenifer Piesse ◽  
Johann Strauss

We investigated the effect of heat and moisture stress on total factor productivity in crop farming under experimental farm conditions. Heat stress is the number of days during the growing season during which the maximum temperature exceeds 24.9 °C. Total rainfall is treated as a basic factor of production and periodic moisture stress, or lack thereof, is the number of rainfall days during the growing season. All models controlled for the cumulative soil benefits arising from minimum tillage, which is the main objective of the experiment. Model specification was evaluated using likelihood ratio tests and three are worthy of note. The study site received 329 mm of rainfall on average on 22 rainy days per season during the period 2002–2015, while the maximum temperature typically rose above 24.9 °C on 33 days per growing season. The average efficiency of the plots in the long-term crop rotation experiment increased at 3.4% per year from a base of 60% to the most recent level of 78%. Neither heat nor moisture stress changed significantly over the study period. Heat stress was found to reduce efficiency by 1.75% per hot day and rainfall increased efficiency by 1.45% for each additional rainy day. However, the interaction of heat and moisture stress lowered productivity overall.


1997 ◽  
Vol 6 (5-6) ◽  
pp. 409-413 ◽  
Author(s):  
Anna-Liisa Varis

A long term survey of Lygus populations (Heteroptera, Miridae) was carried out on eight arable crops in southern Finland. Sweep net samples were taken weekly during the growing season in 16 successive years. The hibernated adults first appeared in May on overwintered crops: winter rye, red clover-timothy ley and winter turnip rape. Turnip rape and ley harbored the most Lygus adults until the end of June even if some of them started to move to spring cereals (wheat, oats and barley), potato and sugarbeet after the emergence of these plants. The numbers of adults on cereals remained small until the crops reached the heading stage. The peak occurred in the first half of August. The adult numbers on potato and sugarbeet were also highest in August. The total number of adults was highest on wheat. Nymphs were found on all the studied crops. They were first captured in the second half of June and reached a peak between mid-July and mid-August. Numbers were highest on wheat. The most common species on all crops was L. rugulipennis Poppius, constituting 92% of the adults. The other Lygus species were L. gemellatus (Herrich-Schaeffer), L. pratensis (L.) and L. punctatus (Zetterstedt). A few specimens of L. wagneri Remane were also found.


2010 ◽  
Vol 49 (4) ◽  
pp. 604-618 ◽  
Author(s):  
Budong Qian ◽  
Xuebin Zhang ◽  
Kai Chen ◽  
Yang Feng ◽  
Ted O’Brien

Abstract A set of agroclimatic indices representing Canadian climatic conditions for field crop production are analyzed for long-term trends during 1895–2007. The indices are categorized for three crop types: cool season, warm season, and overwintering. Results indicate a significant lengthening of the growing season due to a significantly earlier start and a significantly later end of the growing season. Significant positive trends are also observed for effective growing degree-days and crop heat units at most locations across the country. The occurrence of extremely low temperatures has become less frequent during the nongrowing season, implying a more favorable climate for overwinter survival. In addition, the total numbers of cool days, frost days, and killing-frost days within a growing season have a decreasing trend. This means that crops may also be less vulnerable to cold stress and injury during the growing season. Extreme daily precipitation amounts and 10-day precipitation totals during the growing season have been increasing. Significant trends associated with increased availability of water during the growing season are identified by the standardized precipitation index and seasonal water deficits. The benefit of the increased precipitation may have been offset by an upward trend in evaporative demand; however, this would depend on the amount of growth and productivity resulting from increased actual evapotranspiration.


2021 ◽  
Author(s):  
Ed Durner ◽  
Ed Rutgers Durner

Abstract Plants of many horticultural crops consist of multiple genetic systems, two or more distinct genotypes joined together as a single plant. The components are identified as the rootstock, interstem and scion. Grafting and budding are the processes that combine these components to establish vascular continuity between them to produce a single plant. Grafting may be natural or human initiated, forced grafting. This datasheet will mainly consider forced grafting with only a brief discussion of natural grafting. The rootstock is that component of the plant that fuses with the scion and provides the plants root system. Other terms used to describe this lower portion of the plant include stock and understock. Stock is synonymous with both rootstock and understock. Understock implies that the lower portion of the plant provides both the root system and some of the trunk while rootstock or stock implies that only the root system is provided by the lower piece. When grafting is performed high on the rootstock, the rootstock may also provide scaffold limbs. The scion is the plants shoot system. It is the component that produces the desired commodity in most cases, which are usually flowers or fruit. In perennials, the scion is nearly always vegetatively propagated. In grafted vegetables, the scion is usually propagated via seed. An interstem is a third genetic component of some grafted plants and is often selected to provide compatibility between the rootstock and the scion. Both grafting and budding combine dissimilar genotypes into one plant. Budding is a form of grafting where a single vegetative bud is used as the scion or interstem. Grafting refers to the condition where more than one bud on a common stem piece are combined with the rootstock or interstem. Perennial ornamental and fruit crops are the grafted crops that are familiar to most horticulturists. Annual vegetable crops are increasingly being grown as grafted plants and interest in using them in commercial production is rising steeply. Short lists of common rootstocks for a number of ornamental, fruit, nut and vegetable crops are presented in Tables 1-3 (at the bottom of this article). These lists are by no means complete, but provide an insight into the large number of rootstocks available in modern horticultural production. Specific recommendations for an area should be obtained from local experts. Good rootstocks should possess as many of the following crop appropriate characteristics as possible: affordable, long term graft compatible, easily propagated, promotes precocity and productivity, controls scion vigour, conveys pest resistance, improves stress tolerance, and has minimal suckering.


2018 ◽  
Vol 80 (02) ◽  
pp. 067-071
Author(s):  
Gaoli Liu ◽  
Ganjun Kang ◽  
Songping Xie ◽  
Haifeng Hu ◽  
Jie Huang

Objectives To investigate the long-term relationship between intraoperative temperature changes of the palm, treatment effects and compensatory hyperhidrosis (CH). Methods We retrospectively analyzed the data of 41 patients with palmar hyperhidrosis who underwent bilateral endoscopic sympathicotomy 3 to 6 years ago. Before and after the operation, changes in ipsilateral palm temperature were monitored and recorded to evaluate the curative effect of the sympathicotomy. Results All operations were performed successfully. Concerning cure, there was no statistically significant difference between patients with different maximum temperature (Tmax) values (p = 0.455). There was a very weak correlation between postoperative palm temperature (34.309 ± 1.377°C) (p = 0.049; correlation coefficient − 0.218). The T3 + T4 sympathicotomies had a higher Tmax (p = 0.000). The incidence and degree of CH had no relationship with Tmax in the left (p = 0.266 and p = 0.168, respectively) or the right hand (p = 0.640 and p = 0.824, respectively). Conclusions Temperature change has a relationship with surgery, but it cannot directly predict the long-term curative effect of a sympathicotomy or the occurrence of CH. Additional studies are required.


2020 ◽  
Vol 25 (4) ◽  
pp. 323-330
Author(s):  
E. S. Ovcharenko ◽  
V. V. Erichev ◽  
S. I. Risovannij ◽  
T. V. Aksenova ◽  
S. V. Melekhov ◽  
...  

Relevance. A long-term inflammation in the oral cavity, unreasonable treatment of periodontal patients with antibiotics cause imbalance between certain types of fungal-bacterial associations accompanied by oral dysbiosis and change of local immune status. So, development and application of new comprehensive diagnosis and treatment techniques in periodontal patients, use of products for correction of microbiota and local immunity are a current and a long-term task. Purpose is to optimize the comprehensive treatment protocol of inflammatory periodontal diseases by introducing probiotics and evaluation of oral microbiome and cytokine profile.Materials and methods. 140 patients were examined. Of these 60 patients had chronic generalized plaque-induced gingivitis and 60 patients suffered from moderate chronic generalized periodontitis. Bacterial and fungal microbiome was assessed and the host immune response was evaluated in all patients before and after the treatment. Half of the patients were treated conventionally and the other half were treated according to a modified scheme: probiotic “Bifidumbacterin Forte” was added.Results. A large number of yeast-like fungi Candida and commensal bacteria were detected in periodontal pockets of patients with chronic generalized plaque-induced gingivitis and moderate chronic generalized periodontitis. That correlates with a significant increase of pro-inflammatory cytokines (TNF-α, IL—8), decrease of concentration of INF-γ and increase of antiinflammatory cytokine IL-4.Conclusion. Changes in clinical, microbiological and immunological values during a modified combination therapy with a probiotic and during a conventional treatment demonstrated that effectiveness of treatment of chronic gingivitis and chronic periodontitis increased by 40% and 37% respectively.


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