Tomatoes, cv. Agriset 761, were grown in Spring and Fall 1996 at three compost rates, 0x, 1x and 2x (1x = 12 t·ha-1). Production system was the full-bed polyethylene mulch with micro- (trickle-) irrigation. The crop in each treatment received (kg·ha-1) 73 N, 34 P, and 121 K from preplant dry, and 225 N and 372 K from injected liquid fertilizers in 117 days during the spring and in 107 days in the fall. Plant growth (plant height) was best with the lx compost rate. Fruits were harvested five times in the spring and four times in the fall. Compost amendments in both seasons delayed fruit maturity. In the spring, marketable yields in the first two harvests were higher (P < 0.05) without than with compost. For the season, marketable yields (t·ha-1) were 57 with 0x, 71 with 1x, and 77 with 2x compost rate (P < 0.001). In the fall, yield differences were smaller or nonsignificant among the treatments and marketable yields for the season were highest with the 1x compost rate.
Green cauliflower (Broccoflower) (Brassica oleracea L. Botrytis Group cv. Alverda) is a relatively new vegetable crop in the United States. Experiments were initiated to investigate the yield potential of `Alverda' green cauliflower in three consecutive plantings (10 Oct. and 24 Nov. 1992 and 12 Jan. 1993) at two in-row spacings (31- and 38-cm) with the factorial combinations of N and K at 98, 196, and 294 kg·ha–1 under subtropical conditions. Crops were grown in an Eau Gallie fine sand with the full-bed polyethylene mulch-seepage (modified furrow) irrigation system. Marketable yields were highest in the January planting with N at 294 kg·ha–1 when 71% of the plants had marketable size (≥0.34 kg) and desirable quality curds. Yields were higher at 38- than at 31-cm spacing. Yields and curd size increased with increasing N rates at all three planting dates (P ≤ 0.01). Potassium rates had no significant effect on yields.
Crops that are produced without manufactured fertilizers and protected from plant pests and weeds without manufactured chemicals are gaining in popularity among consumers. Non-chemical methods of plant protection, such as the development of biocides from plants, would be desirable for environmental and economic reasons and because of pesticide tolerance of some plant pathogens and insects. Extracts and their individual ingredients from several plant species have been used experimentally against plant pathogenic bacteria, insects, and weeds. There are problems, however, that make the use of biocides difficult: low concentration of active ingredients in the plants; purification of active ingredients from dozens of secondary compounds; instability of the active ingredients when exposed to light and air; and the mode of action is little understood or unknown. The technological and scientific advances that could allow the use of non-chemical based plant protection systems and the problems with such systems will be considered and discussed.
A. A. Csizinszky
Italian parsley (parsley) Petroselinum crispum, summer savory (savory) Satureja hortensis, sweet marjoram (marjoram) Origanum majoranna, and thyme Thymus vulgaris, were evaluated for their yield potential in multiple harvest during the fall–winter–spring (Dec.–May 1997–98). The herbs were grown with the full-bed polyethylene mulch-micro (trickle) irrigation system. Experimental design was a split-plot arranged in three randomized complete blocks. Main plots were two N–P–K treatments: 0 N–P–K or N and K from a liquid 4N–0P–3.32K fertilizer injected at 0.77 N and 0.64 K kg/ha per day. In the subplots, compost was applied in a 4 to 8 inches wide band on the pre-bed at 0x, 1x, 2x, and 4x rates (1x = 4.5 t·ha–1). Parsley and marjoram yields in the first three harvests and thyme yields in the first two harvests were similar with 0x compost and N + K injected fertilizers to yields with 3x and 4x compost rates with no injected N + K fertilizers. For the season, yields were higher with injected N + K fertilizers with or without compost, than in the compost treated plots with no N + K fertilizers.
A. A. Csizinszky
Two tomato (Lycopersicon esculentum Mill.) cvs. Agriset 761 and Equinox, were grown in spring and fall 1996 with two microirrigation rates 1x (HI) and 0.75x (LO) of the open pan evaporation and sprayed either weekly or biweekly with Anti-Stress 2000 (acrylic polymer) at 2.33 L·ha–1 in 280 to 561 L·ha–1 H2O during the first 10 weeks of the season. Tomato yields were similar with HI or LO irrigation rate and with antitranspirant sprays or water control. In both seasons, `Equinox' had a higher early but lower seasonal total marketable yield than `Agriset 761' (P ≤ 0.05). Residual soil concentrations of NO3-N and K were higher (P ≤ 0.05) with the LO, than with HI irrigation rate.
Alexander A. Csizinszky
Alexander A. Csizinszky
Tomato, Lycopersicon esculentum Mill. `Asgrow 1035', was planted in Summer–Fall (Aug.–Dec.) 1998 in a land previously amended with compost in Fall 1997 and then cropped in sequence with three vegetables during the Fall–Winter–Spring 1997–1998. Soil was an Eau Gallie fine sand, and the production system was a full-bed polyethylene mulch with micro-(trickle) irrigation. Experimental design was a split-split plot replicated three times. Main plots were N and K fertilizer treatments for the Fall 1998 tomato crop: fertilized (FT 98) or nonfertilized (NF 98). Subplots were two N–P–K treatments for the Fall 1997 tomato crop: fertilized (FT 97) or nonfertilized (NF 97). Sub-subplots were four compost rates 0x, 1x, 2x, and 3x (where 1x = 10 t·ha–1 `Disneyworld' compost) that were applied for the Fall 1997 tomato crop. Fruit size and yields were best in the plots that received N and K in Fall 1998 (FT 98) and N–P–K in Fall 1997 (FT 97). Early yields (harvests 1 + 2) were highest with the 2x and seasonal total yields (six harvests) were highest with the 3x compost rate. Very high residual soil P and Fe concentrations were detected with increasing compost rates.
Alexander A. Csizinszky
Sweet marjoram [(marjoram) Origanum majoranna], Italian parsley [(parsley) Petroselinum crispum], Summer savory [(savory) Satureja hortensis], and thyme (Thymus vulgaris) were evaluated for their yield potential during Fall–Winter–Spring (Oct.–May) 1998–99. The herbs were grown in a light sandy soil with the full-bed polyethylene mulch-micro(trickle) irrigation system. Experimental design was a split-plot replicated three times. Main plots were two N–P–K treatments: 0 N–P–K or N and K from a liquid 4–0–3.32 (N–P–K) fertilizer injected at 0.77 N and 0.64 K kg·ha–1·day–1. Sub-plots were four compost rates at 0x, 1x, 2x, and 4x (1x = 4.5 t·ha–1). Early and seasonal total yields of marjoram and savory were similar with injected N + K and 0x compost to yields with compost and with or without injected N + K fertilizer. Yields of parsley and thyme increased with increasing compost rates and were best with compost plus liquid N + K. Postharvest soil concentrations of NO3-N were lower in the parsley, than in the marjoram, savory and thyme plots. Residual concentrations of all other elements were similar with or without injected N + K or compost treatments.