The effect of applying phenamiphos and oxamyl by drip irrigation for the control of the reniform nematode on pineapple in Hawaii
1980
Apt, W.J.
Phenamiphos, applied monthly for 16 months at 1.7 and 3.4 kg a.i. in 664 hl of water per hectare without a preplant 1,3-D fumigant produced a plant crop of 124 and 125 metric tons/ha (fresh fruit), respectively, compared to 100 tons from the irrigated control. The percent of 2 1/2 fruit and sucker size was significantly greater for the phenamiphos treatments. At the same rates supplementing 1,3-D preplant fumigation (3.74 hl/ha), the yields were 140 and 136 metric tons/ha compared to 129 tons for the irrigated-fumigated control. The percent of 2 1/2 fruit and sucker size was significantly greater than the control, however, the data indicated that phenamiphos applied at 3.4 kg/ha had an inhibiting effect on yield and sucker size compared to the 1.4 kg rate. Oxamyl applied monthly at the same rates of 1.7 and 3.4 kg/ha without a preplant 1,3-D fumigant produced 111 and 113 metric tons/ha, respectively, compared to 100 tons from the irrigated control. The percent of 2 1/2 fruit was similar to that obtained from the irrigated control, however, sucker size was significantly greater than the control. At the same rates supplementing a 1,3-D preplant fumigant, the yields were 128 and 124 metric tons/ha, respectively, compared to 129 tons for the irrigated-fumigated control. The percent of 2 1/2 fruit and suckers size was significantly less than the control. While oxamyl gave good nematode control, the yields, fruit size and sucker growth indicated a retarding effect when supplementing a preplant fumigation. Lower rates and reduced applications are necessary to offset this effect.
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