Joginder Singh

Wheat breeding, productivity and slow variety change: evidence from the Punjab of India after the Green Revolution *

Variety change and genetic diversity are important means of combating crop losses from pests and diseases in modern agricultural systems. Since the Green Revolution, genetic diversity among wheat varieties released in India has increased but variety change on farms continues to be slow. In this article, we define and summarise indices of variety change and genetic diversity for the wheat varieties released and grown in Indian Punjab during the post-Green Revolution period. We evaluate the effect of each index on technical efficiency with a Cobb-Douglas yield model after testing for exogeneity. Findings support the hypothesis that slow variety change has offset the positive productivity effects of diversifying the genetic base in wheat breeding during the post-Green Revolution period. Policies that speed the rate of variety change and contribute to a more equitable spatial distribution of modern varieties could support wheat productivity in the Punjab of India, reinforcing plant breeding successes.

Enzymic hydrolysis of rice straw by crude cellulase from Trichoderma reesei

Abstract The cellulase system with a maximum FP cellulase activity of 1·30 IU/ml obtained from fermentation by T. reesei of alkali treated, steamed rice straw was employed at 26 FPU g−1 substrate for enzymatic saccharification. Production of reducing sugars (as glucose) at 268·5 mg−1 of rice straw treated with 4% sodium hydroxide in combination with 60 min of steam pressure (1·05 kg cm−2) was obtained in 48 h of incubation. Analysis of variance applied to the results of the effects of various factors revealed that a substrate concentration of 4% (w/v), a pH of 5·0, a temperature of 50°C, an enzyme concentration of 25 FPU g−1 substrate and a time of 48 h, were optimum for the production of the maximum amount of reducing sugars; 268·5 mg g−1 of pre-treated rice straw representing a maximum saccharification of 54·3% (cellulose basis).

Effect of insecticidal sprays on the plant and secondary pest inductions in Hirsutum cotton in Punjab

Abstract Four insecticides, viz. Ripcord 10 EC (cypermethrin), Sevimol 40 LV (carbaryl), Thiodan 35 EC (endosulfan) and Phendal 50 EC (phenthoate), which are recommended for bollworm control on Hirsutum cotton in Punjab, were screened for their possible effects on the plant and on the induction of secondary pest problems. None of the insecticides influenced the production of monopods, sympods and plant height. Leaf analysis from different treatments showed a reduction in total soluble sugars and total nitrogen. Endosulfan-treated leaves showed significant reductions in total proteins and total soluble sugars as compared with the untreated control crop. None of the insecticidal treatments induced angular leaf spot and vein blight, Alternaria and Myrothecium plant diseases. Both carbaryl and cypermethrin, however, induced the build-up of red spider mite, Tetranychus cinnabarinus (Boisduval).

Effect of plant phenology and related factors on insect pest infestations in Arboreum and Hirsutum cotton varieties

Phenology of Arboreum varieties: G 27, LD 133 and LD 230 differed from Hirsutum, F 414 under unsprayed conditions in Ludhiana. Protection to Arboreum varieties at seedling stage against grasshopper and to bolls formed between 1 August to 15 September against bollworm damage was found necessary. In Hirsutum variety, F 414 bolls formed between 16 August to 15 September needed maximum protection from bollworm damage.At vegetative phase, jassid population was positively correlated with the leaf size and negatively with number of gossypol glands and leaf thickness, and that of whitefly was positively correlated with number of leaves per plant. Six plant morphological characters: number of leaves, squares, bolls, vegetative and reproductive branches and shoot pubescence-affected bollworm infestation significantly and the effect was related to and varied with the age of the plant. Anthocyanin pigment was not detected in any plant part in the four cotton varieties. At vegetative and reproductive phases, gossypol, total phenols, condensed tannins, ieuco-anthocyanins and flavenols in leaf, shoot and boll per se did not influence insect pest infestations under field conditions. The parasite population was not related to pest infestations throughout the plant growth. Predation rates, however, on pest populations seemed to be considerable. Sclereids and lignified cells affected penetration of first instar Earias vittella larvae into bolls.RésuméA Ludhiana, la phénologie des variétés de VArboreum G 27, LD 133 et LD 230 différait de celle de la variété Hirsitum F 414 dans des conditions de non pulvérisation des plantes. Il a été nécessaire de protéger les variétés d’arboreum au stade de germination contre la sauterelle. On a aussi protégé les graines formées entre le 1 août et le 15 septembre contre les vers. Dans la variété Hirsitum F 414 les graines formées entre le 16 août et le 15 septembre ont requis une protection maximale contre les attaques des vers.Au stade végétatif, une corrélation positive a été établie entre la population des jassidés et les dimensions de la feuille. Une corrélation négative fut trouvée entre la même population de jassidés et le nombre de glandes de gossypol et l’épaisseur de la feuille. Entre la population de whitefly et le nombre de feuilles par plante, la corrélation était positive. Six charactères morphologiques de la plante, le nombre de feuilles, squares, graines, branches végétatives et reproductrives et la pubéscence des pousses ont affecté sensiblement l’infestation causée par les vers et l’effet était lié à l’âge de la plante et variait avec celle-ci. Dans les quatre variétés du cotton, aucune partie de la plante ne contenait de pigment d’anthocyanine. Aux stades reproductifs et végétatifs le gossypol, les phénols, les tannines condensés, les leuco- anthocyanines et les flavénols dans la feuille, la pousse et la graine n’ont pas influé sur l’infestation des plantes par les insectes dans les champs d’expérimentation. La population des parasites n’avait aucun rapport avec l’infestation causée par les insectes durant la croissance de la plante. Cependant l’effet des prédateurs sur les populations des insectes semblait considérable. Les scléroides et les cellules lignifiées affectaient la pénétration des larves Earias vittella dans les graines.

Temporal changes in the dispersion of populations of three homopterous insect pests of upland cotton

Spatial pattern of distribution of populations of three insect species, namely, Amrasca biguttula biguttula (Ishida), Bemisia tabaci (Genn.) and Aphis gossypii Glov. was studied in Upland cotton (Gossypium hirsutum L.) at an interval of 13–15 days during July, August and September in Punjab. The populations were found to be aggregated from the beginning of season upto 25 August in jassid nymphs, 12 August in whitefly adults and the end of season in apterous aphids. Environmental heterogeneity at low population in July and innate behaviour at high population were responsible for the aggregated dispersion in each of the three homopterans. Based on these observations the appropriate number of samples required to be drawn for population studies were determined which varied with change in pest density in each case.RésuméLa distribution de la population de 3 especes d’insectes, Amrasca biguttula biguttula (Ishida), Bemisia tabaci (Genn.) and Aphis gossypii Glov. fut analysée sur le coton (Gossypium hirsutum L.) durant un intervalle de 13 à 15 jours pendant le mois de Juillet, Aout et Septembre au Punjab. Les populations etaient aggregées du debut de la saison au 25 Aout pour les chrysalides, au 12 Aout pour les adultes et a la fin de la saison pour les aphides sans ailes. L’heterogènite de l’environnement pour la population au bas niveau au mois de Juillet et le comportement inné pour les populations au niveau elèvé furent responsable de l’aggregation dispersee de chaque groupe d’hemiptères. Se basant sur ces observations, le nombre approprié qu’on necessite pour l’analyse fut determine dans chaque cas ou il y a un changement dans la densite des ravageurs.

A sensitive colorimetric method for the microdetermination of flavonols

SummaryA colorimetric method for the quantitative determination of flavonols has been developed. The method is based on the reaction of the antimony(III) complex with flavonols to form an intensely yellow colour. The metal-flavonol complex has an absorption maximum at 410 nm. The Lambert-Beer law is obeyed in the concentration range of 0.4–6μg/ml for quercetin and the method is quite reproducible. Catechins, flavones and flavonol glycosides and some of the phenolic acids do not interfere. Individual flavonols can be efficiently separated by paper chromatography and estimated after elution from the chromatographic paper. Our results show that in the metal-complex formation, the 4-carbonyl and 3-hydroxy groups of the flavonols are involved. This method does not involve pH adjustment (which is not considered desirable in case of flavonols).ZusammenfassungEine kolorimetrische Methode zur Bestimmung von Flavonolen wurde ausgearbeitet. Sie beruht auf der Bildung des intensiv gelb gefärbten Komplexes von Sb(III) mit Flavonolen, dessen Absorptionsmaximum bei 410 nm liegt. Die Farbe entspricht zwischen 0,4 und 6μg Quercetin/ml dem Lambert-Beerschen Gesetz. Die Ergebnisse sind gut reproduzierbar. Catechine, Flavone, Flavonolglucoside sowie einige aromatische Hydroxysäuren stören nicht. Die einzelnen Flavonole lassen sich papierchromatographisch gut trennen und nach Elution bestimmen. Nach den Ergebnissen dieser Arbeit sind die 4-Carbonyl- und die 3-Hydroxygruppe an der komplexen Bindung des Metalls beteiligt. Das Verfahren erfordert keine Einstellung des pH, die im Fall der Flavonole auch nicht wünschenswert ist.