Evaluation of design methods for side resistance only rock socketed piles

The ability of three methods to predict the load-settlement response of rock socketed piles was examined in a recent paper. The piles considered were complete piles in which both the side and base of the piles contribute to the total resistance. For a range of reasons, it is sometimes necessary to consider rock socketed piles for which the resistance is provided only by the side of the socket. This paper extends the earlier paper by comparing predictions for side resistance only piles with the load-settlement response of a suite of full-scale side resistance only pile tests. Only two of the methods of the earlier paper are used for this comparison as the third method could not decouple the two components of resistance. It is demonstrated that one of the methods produces reasonable predictions of performance whereas the other appears to underpredict performance.

Characterization of Components of Resistance to Corn Stunt Disease

Considering the occasional but increasing presence of corn stunt disease in the subtropical region of Argentina, the objective of this research was to devise an effective strategy to screen disease-resistant genotypes in the absence of high and constant natural pressures. To do so, the presence of antixenosis and antibiosis as components of resistance to vector Dalbulus maidis (DeLong 1923) as well as resistance to the pathogen Spiroplasma kunkelii (Whitcomb et al. 1986) under artificial inoculation conditions were investigated in four widely-distributed maize hybrids in Argentina. The hybrids shown differences in the levels of resistance and target organisms (either the insect vector or the pathogen). Antixenosis and antibiosis to D. maidis were observed in DK72-10. Resistance of DK79-10 to S. kunkelii was evidenced by a delayed onset of symptoms, and DKB390 was antixenotic to D. maidis and highly resistant to S. kunkelii. A good association was found between symptom severity and yield, but not between symptom severity and accumulation of pathogen S. kunkelii. In conclusion, the proposed methodology was efficacious and can aid the screening of resistant genotypes in breeding programs to reduce the impact of corn stunt disease, ensuring that hybrids with good resistance level will be planted by farmers whenever disease occurs.

Morpho Physico-Chemical Components of Resistance to Pod Borer, Helicoverpa armigera (Hübner) in Pigeonpea [Cajanus cajan (L.) Millspaugh]

The experiments were conducted at CCS HAU, Hisar (Haryana) to study the morpho physico-chemical components of resistance to pod borer, Helicoverpa armigera in pigeonpea with different sowing dates. In different four sowing dates, the minimum pod infestation (1.70%) was recorded in (D4) 3rd week of July sown crop, whereas, it was observed maximum (4.54%) in (D2) 1st week of July sown crop. In different pigeonpea varieties, the minimum mean pod infestation (2.45%) was recorded in AL-201, whereas, the maximum mean pod infestation (3.72%) was recorded in Pusa-992. The glandular (type A) and non-glandular (type B) trichomes on pods of top and middle canopy of the plant and pod wall thickness were associated with resistance to H. armigera, whereas, the non-glandular lengthy (type C) trichomes and pod length were associated with susceptibility to this insect. The expression of resistance to H. armigera was also associated with the high amount of fat, phenol and tannin content. Crude protein and total soluble sugar content were responsible for higher pod infestation.