Artichoke, a cool-season, frost-tolerant, but freeze-sensitive, crop, was investigated for annual production in Utah. The objectives were to assess the effects of alternative cropping methods on growth and productivity. Artichoke (`Imperial Star') was seeded in January or February and grown for 3 months before transplanting to the field. Plants were planted in bare soil, through plastic mulch or through plastic with floating rowcovers in April or May. Plant growth (leaf area), environmental conditions, and yield (number, weight, and quality) were monitored throughout the year. Planting date and mulching treatments had a significant effect on plant growth and productivity. Leaf area was greatest at all measurement dates as temperature adjacent to the plant increased (plastic with cover > plastic > bare soil). Early planting had greater yield than late planting regardless of mulching treatment. There was no difference in final yield between the plastic mulch and plastic plus cover at early plantings, although yields were higher than in bare soil. However, late planting through plastic with rowcovers significantly reduced bud yields compared to bare soil or black plastic only. While higher temperatures associated with plastic and rowcovers increased plant growth, increased temperatures under covers after the May planting date devernalized artichoke seedlings, which contributed to the lower yields late in the season.
D.T. Drost, N. Philips and N. Thomsen
D.T. Drost and H.C. Price
Tomatoes (Lycopersicon esculentum Mill.) were grown in conventional tillage (CT), rye (Secale cereale L.) mulch no tillage (RNT), and wheat (Triticum aestivum L.) mulch no tillage (WNT). Either germinated seeds (GS) or raw seeds (RS) were fluid drilled on several dates in 1981 and 1982. Tomato stands in no tillage (NT) generally were equal to or higher than in CT, and stands improved with later plantings in each year. Plant stands were unaffected by GS and RS. Time to 50% emergence (T50) was up to 4 days less in NT than in CT and 2 to 3 days less from GS than RS. Yields with CT were twice as high as those with NT for early planting dates. Yields decreased in CT with successive planting dates to levels equal to NT plantings. Use of GS increased fruit yields as compared to RS, regardless of the planting date.
D.T. Drost, J.W. Macadam, L.M. Dudley and N. Soltani
Groundwater, contaminated with sulfur (S) at concentrations higher than allowable for drinking water, may be suitable for irrigation. Our objectives were to determine the growth response and mineral uptake of two vegetables grown in high-S irrigation water. Bean (Phaseolus vulgaris) and broccoli (Brassica oleracea L.), grown in 8-L pots containing a calcareous sandy loam, were irrigated with waters containing from 58 to 582 mg S/L. Plants were harvested and growth was measured at 4, 8, or 12 weeks. Soil paste extracts and dry plant tissue were analyzed by inductively coupled plasma (ICP) spectroscopy at each harvest. Bean shoots and pod dry weight decreased by 32% and 28%, respectively, as S concentration increased. Although final pod number was not affected by the irrigation treatments, pod yields (4 weeks) decreased as S concentration increased. Broccoli growth was not affected by increasing S concentration at any of the harvest dates, though head diameter did decrease as S increased. Magnesium, sodium, and sulfur accumulated in shoot tissue (leaves and stems) of both species in proportion to their concentration in the irrigation water. It appears that high-S waters can be used to grow these vegetables without negative effects on growth.
D.T. Drost, J.W. MacAdam, L.M. Dudley and N. Soltani
Groundwater contaminated with sulfate (SO4 2−) at concentrations greater than allowed for drinking water may be suitable for irrigation. Our objectives were to determine the growth response and mineral uptake of two vegetables grown with high SO4 2− irrigation water. Bean (Phaseolus vulgaris) and broccoli (Brassica oleracea L.) were grown in a calcareous sandy loam soil irrigated with water containing 175 to 1743 mg SO4 2−/L. Plants were harvested and growth was measured at 4, 8, or 12 weeks. Soil paste and dried ground plant tissue extracts were analyzed for elemental composition at each harvest by inductively coupled plasma spectroscopy. Bean shoot dry mass decreased as SO4 2− concentration increased. Although pod number at 4 weeks decreased as SO4 2− concentration increased, pod number at 12 weeks was not affected by irrigation treatments. Broccoli growth was not affected by increasing SO4 2− concentration at any of the harvest dates, although head diameter decreased as SO4 2− increased. Magnesium, sodium, and sulfur accumulated in shoot tissue (leaves and stems) of both species in proportion to their concentration in the irrigation water. Soil Na and electrical conductivity levels increased as SO4 2− concentration increased even with a 20% leaching fraction. These results suggest that bean and broccoli can be successfully grown with high-SO4 2− irrigation water.