EFFECT OF SOME HERBICIDES AND MULCHING TREATMENTS AS NATURAL ALTERNATIVES USED FOR WEED CONTROL AND PEA (Pisum sativum L.) PRODUCTIVITY WITH MONITORING HERBICIDE RESIDUES.

Abstract

A two-year field experiment was carried out at Sids Horticulture Research Station during 2015/2016 and 2016/2017 winter seasons to study the effect of thirteen weed control treatments. The treatments were Amex 2.5 l/fed., Amex1.875 l/fed. followed by one hand hoeing at 40 days after sowing; Ultra afalon 1L/fed., Ultra afalon 0.750 l/fed. followed by one hand hoeing at 40 days after sowing; Stomp extra 1.7 l/fed., Stomp extra 1.275 l/fed. followed by one hand hoeing at 40 days after sowing, Gesagard 1.5 l/fed., Gesagard 1.125 l/fed. followed by one hand hoeing at 40 days after sowing; mulching by black, green and transparent polyethylene sheets, hand hoeing twice at 20 and 40 days after sowing as compared with unweeded check in complete randomized blocks design with three replicates on weeds, pea yield and its components. Herbicide residues were also monitored by HPLC chromatography in seed green pea. Results show that the best treatments for controlling total annual broad leaf and grassy weeds and the highest yield correlated negatively with weed biomass as g/m 2 and positively with yield components of pea with mulching by black and green polyethylene sheets and exceeded applied soil acting herbicides of Amex, Ultra afalon, Stomp extra and Gessagard and were almost equal to the above mentioned reduced rates of these herbicides followed by hand hoeing. For herbicide residues detection in green pea seeds was found to be below the maximum residue limit with single herbicide or their reduced rates combined with one hand hoeing. Both Ultra afalon or Gessagard treatments residues were lower than Stomp extra or Amex herbicides. Stomp extra 1.275 l/fed. followed by one hand hoeing at 40 days after sowing and mulching by black polyethylene were the best treatments for weed control and pod green yield in both season. The highest fresh pod yield (ton/fed.) or seed yield (kg/fed.) and correlated negatively with the different studied weed categories. Gessagard followed by one hoeing or Stomp extra followed by one hoeing and mulching by black polyethylene treatments were economically feasible than other weed control treatments. Mulching by black and green polyethylene sheets can be recommended as a good and clean alternative for weed control by herbicides in pea crop and can be used in organic farming systems.