Gypsum and Compost Effects on Sugarcane Root Growth, Yield, and Plant Nutrients

In rockwool-grown greenhouse vegetables, unsatisfactory spatial root development, rapid root collapse, and increased incidence of root diseases are very common. Improved water management could alleviate these problems to some extent, because this could favorably modify water-air distribution in the slab, thereby improving greenhouse vegetable yield and quality. The present study tested six irrigation strategies on the productivity of rockwool-grown tomatoes (cv. Rapsodie) during Jan.o–Aug. 2004. The four treatments, based on electronic Grodan? water content meters (WCMs), received irrigations when the slab water content (SWC) was ≈60%, 70%, 80%, and 90% while the other two treatments, based on balances, applied irrigations after a 700- or 500-g loss in the daily-adjusted slab weight (LDASW). Initially, we noticed a heterogeneous EC build-up in the slabs across various treatments, which probably distorted the expression of treatment effects (if any) on plant growth, yield, and water use. To minimize this problem, an EC control strategy of applying extra irrigation was devised and adopted in two sequential phases: 1) application of a 30-minute-long extra irrigation twice a week (for 7 weeks); and 2) extra irrigation(s) using the irrigation control routine of an Argus computer when the slab EC was ≈3.5 mS/cm (for 5 weeks). Slab EC was well controlled in both these phases and we observed significant treatment effects on root growth and marketable yield. Analyzing the results, we concluded that irrigating at 70% to 80% SWC was best for maximum root growth as well as marketable yield. The two irrigation treatments based on the 700- and 500-g LDASW were well maintained and performed equally well, producing marketable yields comparable to those produced by irrigating at 70% and 80% SWC.

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Yield, Shoot and Root Growth, and Physiological Responses of Mature Peach Trees to Grass Competition

HortScience ◽

10.21273/hortsci.36.7.1214 ◽

2001 ◽

Vol 36 (7) ◽

pp. 1214-1218 ◽

Cited By ~ 16

Author(s):

Thomas J. Tworkoski ◽

D. Michael Glenn

Keyword(s):

Root Growth ◽

Lolium Perenne ◽

Perennial Ryegrass ◽

Growth Yield ◽

Growth And Yield ◽

Grass Species ◽

Peach Tree ◽

Herbicide Treatments ◽

Peach Trees ◽

Leaf N

Competitive effects of different grass species were evaluated on growth, yield, leaf N, and leaf water potential of 8-year-old peach [Prunus persica (L.) Batsch.] trees and on weed abundance. Two cultivars (`Loring' on Lovell rootstock and `Redhaven' on Halford rootstock) of peach trees were planted in separate orchards in 1987. Nine orchard floor treatments were installed beneath the peach trees in 1995: Festuca arundinacea Schreber (tall fescue); Lolium perenne L., var. Manhattan II (perennial ryegrass); Lolium perenne L., var. Linn; Agrostis gigantea Roth (red top); Dactylis glomerata L. (orchardgrass); Phleum pratense L. (timothy); Bromus carinatus Hook. and Arn. (brome); weedy control; and herbicide weed control (simazine, glyphosate). In general, grasses reduced vegetative growth and yield in both cultivars. Orchardgrass was one of the most competitive species and reduced vertical water sprout length by 15% to 27% and lateral shoot length on fruit-bearing branches by 19% to 30% compared with herbicide treatments. Orchardgrass reduced yield by 37% and 24% in `Loring' and `Redhaven', respectively. All grasses were not equally competitive; `Linn' perennial ryegrass did not significantly reduce growth or yield in `Redhaven'. Control treatments with weeds also did not differ from herbicide treatments in peach tree growth and yield. Grass and weed ground covers consistently reduced peach tree leaf N by at least 10%, compared to herbicide treatment, possibly due to reduced root growth. `Redhaven' root density in the top 10 cm of soil was ≈12 cm·cm-3 in herbicide strips vs. 1 cm·cm-3 in weedy or ground-covered strips. Peach leaf water potential was not affected by grass and weeds. Weed weights were significantly reduced by all grasses compared with weedy control. The results indicate that peach cultivars respond differently to grass competition, but the relative competitiveness of each grass species was similar for both cultivars. Grass competition reduced growth, yield, and pruning weights of mature peach trees, but the reduction in vegetative growth did not significantly reduce pruning time per tree. Grasses that are less inhibitory to peach yield may be useful for weed management in orchards.

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Interactions of boron-toxicity, drought, and genotypes on barley root growth, yield, and other agronomic characters

Australian Journal of Agricultural Research ◽

10.1071/ar00154 ◽

2002 ◽

Vol 53 (3) ◽

pp. 347 ◽

Cited By ~ 7

Author(s):

S. K. Yau

Keyword(s):

Root Growth ◽

Water Supply ◽

Growth Yield ◽

Boron Toxicity ◽

Agronomic Characters ◽

Hordeum Vulgare L ◽

Greenhouse Study ◽

Terminal Drought ◽

Drought Tolerant ◽

Biological Yield

In areas with high levels of soil boron, symptoms of boron (B) toxicity often appear under droughts. This greenhouse study examined the interactions of B-toxicity, drought, and genotypes on barley (Hordeum vulgare L.) root growth, B-toxicity symptoms, B concentrations of straw, and yield. Plants were grown in tubes 65 cm tall. Three factors were studied: B, water supply, and genotypes. There were 2 B levels, B0 v. B50, in the subsoil (20-60 cm). There were 4 levels of water supply: no drought (control), and early, mid-season, and terminal drought. Two barley lines were compared: Sahara (B-toxicity tolerant) and BOL (drought tolerant, B-toxicity sensitive). Significant B-by-drought interaction was detected in straw B concentration, root growth in subsoil, and straw and biological yield for BOL. Mean root growth in the 40–60-cm soil section was much higher under mid-season drought than under the control. At B50, plants under drought had 1-fold higher straw B concentrations and more B-toxicity symptoms than the control plants. This is the first study to provide data to explain the frequent association of B-toxicity symptoms with droughts in the field. The results clearly showed that tolerance to B-toxicity, as well as drought, is needed in dry areas having high levels of subsoil B.

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