Effect of row cover and supplemental Ca fertilization on blossom-end rot in bell pepper (Capsicum annuum var. annuum, Grossom Group)

Graduation date: 1998A 2-year trial was conducted at Oregon State University's Hermiston Agricultural Research and\ud Extension Center to examine the effects of spunbonded row cover and supplemental calcium fertilization\ud on blossom-end rot in two varieties of bell pepper. Blossom-end rot is a common cause of bell pepper yield\ud losses, especially at the first harvest.\ud The experimental design was a complete factorial with Ca fertigation rates at 0, 34 and 68 kg-ha⁻¹\ud (as Ca(N0₃)₂ ), with and without spunbonded polypropylene row cover, and two varieties, 'Vidi'\ud (Vilmoren), and 'Ranger' (Asgrow). Bell pepper seedlings were transplanted into drip-irrigated beds\ud covered with black plastic mulch in May, 1995 and June, 1996. Calcium nitrate was applied in three\ud fertigations with Urea Ammonium Nitrate (32% N) added to total 22 kg N-ha⁻¹, per fertigation. Two\ud 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\ud hoop-supported row cover was applied at transplanting and removed at first harvest.\ud Anthesis was delayed under row cover in 1995. Leaf area and specific leaf area increased under row\ud cover as compared to no row cover, and leaf dry weight was lower with row cover than without in 1995.\ud An increase in the Ca fertilization rate linearly increased leaf dry weight and decreased specific leaf area\ud in 1995, but had no effect in 1996.\ud Tissue Ca concentration was lower in BER-affected fruit than in marketable fruit. Fruit Ca\ud concentration was higher with row cover than without in 1996. Fruit Ca concentration increased linearly\ud as supplemental Ca rate increased in 1995, but was not affected by Ca rate in 1996.\ud Row cover increased first harvest and total yield of marketable fruit, by 1.25 and 4.75 t-ha⁻¹,\ud respectively. Row cover increased the yield of first harvest fancy-grade fruit in 1995. First harvest BER\ud and total BER yields decreased substantially under row cover, but the difference in BER fruit yield\ud between row cover treatments was larger in 1996 than in 1995. The percent BER fruit of total first harvest\ud yield, by weight, decreased from 51% without row cover to 25% with row cover. The percent BER fruit of\ud season total yield decreased from 24% to 15% in 1995, and 26% to 6% in 1996. Yield of first harvest\ud sunscald fruit decreased under row cover for 'Vidi'. Total sunscald fruit yield decreased for 'Ranger' in\ud 1995, and 'Vidi' in 1996, while percent sunscald decreased for 'Vidi' both years under row cover.\ud First harvest fancy-grade and total marketable fruit yields, and total seasonal yield of fancy-grade\ud fruit increased linearly with an increase in Ca rate. First harvest BER and SS-affected fruit yields and first\ud harvest total cull yield decreased linearly as Ca rate increased, as did total seasonal yield of sunscald and\ud total cull fruit