Terbutryne for the control of weeds in fruit and citrus orchards.
Arenstein Z.
Author Affiliation: Agan Chem. Manufacturers Ltd., Ashdod, Israel.
Phytoparasitica 7 : 145-146
Abstract : In 1967 trials were begun with terbutryne (Terbutrex 50 WP) for controlling weeds in young orchards (from planting time onwards) in nurseries and in bearing stone fruit orchards. Trials were performed in: (a) fruit nurseries of apple, pear, plum and peach; (b) citrus nurseries of lemon, pommelo and grapefuit; (c) citrus orchards from the time of planting, and after grafting, Shamouti orange, grapefruit, various mandarins, Valencia orange, Washington navel orange and pommelo; and (d) subtropical fruit orchards, from the time of planting - avocado, mango, persimmon and annona. The soils involved, varied from sand to heavy clay. The rates of terbutryne tested were 2, 2.5, 3 and 4 kg/ha and in citrus nurseries up to 6 kg/ha. The trials were performed with knapsack, motorized knapsack and tractor-driven commercial sprayers. Spray volumes varied from 200 to 500 l/ha. Terbutryne controlled existing weeds and prevented the germination of new weeds for a period of 60-120 days, depending on the time of application and the type of soil. Avena sterilis and Lolium sp. were not controlled completely by terbutryne. Conyza sp. was not controlled by contact sprays. No phytotoxic symptoms were observed in fruit tree nurseries during a period of one year when two consecutive sprays were given (1) in citrus nurseries where young trees were treated with 6 kg/ha, (2) in young and older citrus orchards or (3) in young deciduous orchards, except in a few isolated cases where the spray mixture contacted the foliage of peach trees. (The foliage was damaged when the orchard was sprayed commercially on a windy day and the spray solution drifted onto the foliage.) On subtropical fruit trees, neither young nor older trees were affected by four successive applications of terbutryne, except for persimmon var. Fujo, which showed some leaf chlorosis.