Non-irrigation in Fall and Winter Improves Florida Citrus Fruit Quality

Moderate water stress applied to citrus trees can increase fruit °Brix. Florida citrus growers have been required to use less irrigation as competition for water increases. The goal of this study was to see if irrigation could be eliminated in the fall and winter with few negative consequences. Water stress was imposed over a 3-year period on `Hamlin' and `Valencia' oranges (an early and late variety, respectively) by stopping irrigation in late October and restarting it in March. `Hamlin' fruit was harvested after 2 months of stress and `Valencia' fruit was harvested after 4 to 5 months of stress. In most years, °Brix was increased by water stress. Over a 3-year period, `Hamlin' yield was not affected by the water stress, but `Valencia' yield decreased slightly in the 3rd year. The increase in °Brix is beneficial economically, and, over 3 cm of irrigation water per year can be saved.

Mauro: a mid to late maturing cultivar of biserrula (Biserrula pelecinus)

Mauro is a new mid to late variety of biserrula. It was derived from a single plant selection from a population collected from a harsh and heavily grazed site in southern Sardinia, Italy. The later maturity, lower hard seed level and higher regeneration in the second year of Mauro compared with Casbah will enhance the performance of biserrula in areas with medium to high rainfall where permanent pasture or infrequent cropping are common.

The effect of soybean variety on corn-soybean intercrop biomass and protein yields

Soybean intercropped with corn can produce a high-quality silage, but pods of early maturing soybean varieties usually shatter when harvested, thus reducing the silage protein potential. In 1991 and 1992, an experiment was conducted in Truro, Nova Scotia, and Sussex, New Brunswick, to determine whether later soybean varieties can provide sufficient biomass and protein in intercrops and escape pod losses at harvest. Early, early high protein, medium, late and very late maturing varieties of soybean were grown as monocrops and intercrops with corn. Eight response variables were measured: soybean shoot biomass yield, intercrop shoot biomass yield, soybean shoot protein concentration, intercrop shoot protein concentration, soybean shoot protein yield, intercrop shoot protein yield, soybean seed biomass yield and soybean seed protein concentration. The two later soybean varieties had higher yields than the two early varieties, contributing to higher protein yields in the later varieties than in the early varieties, under both monocropping and intercropping. In contrast to the corn monocrop, intercrops with all soybean varieties produced higher protein concentrations. Under intercropping, only the late variety produced significantly higher protein yields than the corn monocrop; however, none of the varieties resulted in significantly lower biomass yields than the corn monocrop. With the late soybean variety, land equivalent ratios of the intercrop shoot biomass yield and the intercrop shoot protein yield revealed yield advantages of intercrops over monocrops of 21% and 10%, respectively. The late variety resulted in an increased intercrop shoot protein concentration without reducing the intercrop shoot biomass yield, because it was still green enough to be harvested with minimal pod shattering. Key words: Soybean variety, corn-soybean intercrop, biomass, silage protein

Flowering in Pisum: Evidence that Gene Sn Controls a Graft-Transmissible Inhibitor

Under an 8-hr photoperiod scions of an early pea variety of genotype if e sn hr grafted to stocks (with cotyledons) of a late variety of genotype if e Sn hr flowered several nodes later than either intact, decotyledonized, or self-grafted plants of the early variety.

Effects of Photoperiodism and Other Factors on the Improvement of Pigeonpea Varieties

Studies on the effects of photoperiodism and other factors were conducted to obtain information which might be useful in a breeding program with pigeonpeas. The information was sought for accelerating this work in a region where extremes of day-length vary by only 2 hours because of its location in latitude 18°. By shortening the length of day to 8 hours through the use of a darkroom, and planting during the month of February, it was possible to induce flower formation 4 months earlier in two early varieties and 7 weeks earlier in a late variety. However, this short-day treatment did not appreciably affect the time of flower induction in an all-season, or "Totiempo" variety. One-gallon tin-can containers and 10-inch polyethylene bags were found satisfactory for growing pigeonpea plants of different varieties.

Effects of Planting Date, Variety, and Plant Population on the Flowering and Yield of Pigeonpeas (Cajan cajan L.)

Two experiments were conducted in 1954 and 1959 at the Isabela Agricultural Experiment Substation for the purpose of obtaining information for improving certain cultural practices in three pigeonpea varieties. The results of the experiment with monthly plantings of varieties Saragateado, Florido, and Kaki demonstrated that height at time of flowering could be controlled through changes in planting dates. There was a linear reduction in the size of plants at time of flowering as the season of planting was retarded in the course of the year. This suggested the possibility of being able to adjust the size of the plant so as to develop better methods of harvesting by hand or by machine. Disregarding the season of planting, varieties Saragateado, Florido, and Kaki generally bloomed and produced a crop during the months of December, January, and February. However, Saragateado was always a late variety. Variations in planting distances within the row of 2, 3, and 4 feet apart did not affect time of flowering nor yield in a significant way. Kaki is an earlier and higher yielding variety than Saragateado. There is need for developing a substitute variety for Saragateado having a higher yield and producing a later crop.

The interaction of nitrogen supply and plant density in potatoes.

In 1959-61, the total fresh weights of tubers of a late variety increased with increasing plant density up to 70 000-100 000 plants/ha. With denser planting, yields decreased if N was not applied, and there was little or no yield increase with 100 or 200 kg/ha N. The optimal plant density was increased by applying 100 kg/ha N but it was not increased further with higher rates of N. Generally, no favourable interaction of N supply and plant density on yield occurred in early liftings. Weights of >35 mm tubers and total dry weights of tubers were generally affected by N and spacing in the same way as total fresh weights. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Physiological Genetics of Pisum

The grafting of genetically early scions of Pisum sativum var. Massey on genetically late stocks (var. Telephone) leads to flowering at a higher node. In reciprocal grafts, the scions of the late variety flower at an earlier (lower) node.