Abstract:
A 2-year trial was conducted at Oregon State University's Hermiston Agricultural Research and
Extension Center to examine the effects of spunbonded row cover and supplemental calcium fertilization
on blossom-end rot in two varieties of bell pepper. Blossom-end rot is a common cause of bell pepper yield
losses, especially at the first harvest.
The experimental design was a complete factorial with Ca fertigation rates at 0, 34 and 68 kg-ha⁻¹
(as Ca(N0₃)₂ ), with and without spunbonded polypropylene row cover, and two varieties, 'Vidi'
(Vilmoren), and 'Ranger' (Asgrow). Bell pepper seedlings were transplanted into drip-irrigated beds
covered with black plastic mulch in May, 1995 and June, 1996. Calcium nitrate was applied in three
fertigations with Urea Ammonium Nitrate (32% N) added to total 22 kg N-ha⁻¹, per fertigation. Two
additional N fertigations were applied for a total of 112 kg N-ha⁻¹ in 1995 and 90 kg N-ha⁻¹ in 1996. A
hoop-supported row cover was applied at transplanting and removed at first harvest.
Anthesis was delayed under row cover in 1995. Leaf area and specific leaf area increased under row
cover as compared to no row cover, and leaf dry weight was lower with row cover than without in 1995.
An increase in the Ca fertilization rate linearly increased leaf dry weight and decreased specific leaf area
in 1995, but had no effect in 1996.
Tissue Ca concentration was lower in BER-affected fruit than in marketable fruit. Fruit Ca
concentration was higher with row cover than without in 1996. Fruit Ca concentration increased linearly
as supplemental Ca rate increased in 1995, but was not affected by Ca rate in 1996.
Row cover increased first harvest and total yield of marketable fruit, by 1.25 and 4.75 t-ha⁻¹,
respectively. Row cover increased the yield of first harvest fancy-grade fruit in 1995. First harvest BER
and total BER yields decreased substantially under row cover, but the difference in BER fruit yield
between row cover treatments was larger in 1996 than in 1995. The percent BER fruit of total first harvest
yield, by weight, decreased from 51% without row cover to 25% with row cover. The percent BER fruit of
season total yield decreased from 24% to 15% in 1995, and 26% to 6% in 1996. Yield of first harvest
sunscald fruit decreased under row cover for 'Vidi'. Total sunscald fruit yield decreased for 'Ranger' in
1995, and 'Vidi' in 1996, while percent sunscald decreased for 'Vidi' both years under row cover.
First harvest fancy-grade and total marketable fruit yields, and total seasonal yield of fancy-grade
fruit increased linearly with an increase in Ca rate. First harvest BER and SS-affected fruit yields and first
harvest total cull yield decreased linearly as Ca rate increased, as did total seasonal yield of sunscald and
total cull fruit.
