The effects of irrigation, nitrogen fertilizer and the control of pests and pathogens on spring-sown field beans (Vicia fabaL.) and residual effects on two following winter wheat crops

Abstract

Experiments started in 1976Experiments started in , 1977Experiments started in and 1978 on Clay-with-Flints soil at Rothamsted tested the effects of combinations of eight two-level factors on spring-sown field beans. Factors tested, presence v. absence, were irrigation, nitrogen fertilizer, aldicarb, fonofos (dieldrin in 1976), benomyl to the seed bed, permethrin (fenitrothion in 1976), pirimicarb, benomyl foliar spray (not tested in 1976).The main pests and diseases present were nematodes of the genus Pratylenchus, the pea aphid Acyrthosiphon pisum, the pea and bean weevil Sitona lineatus, root blackening associated with the fungal genera Pythium and Fusarium, the foliar diseases chocolate spot, Botrytis spp., rust, Uromyces fabae and bean leaf roll virus.Incidence of these pests and diseases varied between years. Controlling those present increased yield by about 0-7 t grain/ha each year. The difficulty of apportioning this increase to particular pests and diseases is discussed. ' Irrigation increased total dry-matter production and grain yield in 1976 and 1978 but only total dry-matter production in 1977, when grain yield was lost because of lodging. Nitrogen fertilizer had little or no effect.The most favourable combinations of treatments gave yields of 3-4, 5-0 and 6-4 t grain/ha in the 3 years respectively. Small yields in 1976, despite irrigation, were attributed to premature senescence caused by exceptionally high temperatures. It is suggested that with good control of pests and diseases yields of at least 5 t/ha should be attainable on Clay-with-Flints soil without irrigation in years of average temperature and rainfall and yields in excess of 6 t/ha when the soil-moisture deficit is lessened by either above-average rainfall or irrigation.Treatments applied to the beans had little or no effect on two following crops of winter wheat. INTRODUCTIONseasonal variations in yield and to determine the size of yields when known pathological constraints The introduction of residual weedkillers and were removed. The pests under study were nemainsecticides able to control black bean aphids todes and insects, and the pathogens were root and (Aphis fabae Scop.) increased the prospects of foliar fungi and viruses. growing satisfactory crops of spring-sown field Of the migratory nematode genera present in beans (Viciafaba L.). Despite these introductions Rothamsted soils, Pratylenchus Filipjev and small average yield and large seasonal variations Tylenchorhynchus Cobb are known to damage roots are still major problems. Recently additional pests of field beans (Oostenbrink, 1954; Whitehead & and pathogens, whose incidence and ability to Fraser, 1972). Pratylenchus Micoletzsky and Helicause damage differ each season, have been shown cotylenchus Steiner are known to attack barley to attack beans. The experiments described here (Coursen, Rohde & Jenkins, 1958;Taylor, 1960). attempted to control a wide range of these to At Rothamsted the predominant genus attacking determine the extent to which this could lessen field be...

Effect of water stress at different periods on seed yield and water use efficiency of guar under Shambat conditions

“…There was no effect of the treatments on seed weight as was reported by [8] in their experiment, which indicates that the seed size was not affected by the stress. On the other hand, the present result is in disagreement with the finding of [9] who reported a decrease of about 34% in the mean seed weight of the stressed faba bean plants, compared to the fully irrigated treatment. Reduc- tion in seed size was found by earlier workers e.g.…”

THE EFFECTS OF LIGHT AND TEMPERATURE ON THE GROWTH OF AND BALANCES OF CARBON, NITROGEN AND POTASSIUM BETWEEN VICIA FABA L. AND APHIS FABAE SCOP.

“…However, there appears to be a different situation with potassium. V. faba is sensitive to this element and responds positively over a wide range of concentrations (McEwen et al, 1981). In contrast, A. fabae retained little of the ingested K in the present experiment.…”

THE EFFECT OF LIGHT ON THE RELATIONSHIP BETWEEN APHIS FABAE SCOP. AND ITS HOST PLANT, VICIA FABA L.

“…The populations have normally collapsed by the end of August (Cammell & Way, 1982). Long-term monthly means of temperature and radiation at Rothamsted Experimental Station are given by McEwen et al (1981). Mean monthly temperatures for May to August were 11-0, 14-0, 15-8 and 15-6 °C, respectively, and radiation 15-7, 17-5, 15-6 and 13-0 mj m~^ d~^.…”