Petunia × hybrids `Snow Cloud' plants were grown under 25 temperature combinations ranging from 10 to 30C and at photosynthetic photon flux levels of 100 or 200 μmol·s-1·m-2 (6.5 and 13 mol·day-1·m-2, respectively). Days to flower-was a quadratic function of average temperature, with 25C being the optimum temperature for minimal tire-e to flower at 200 μmol·s-1·m-2. Plant height increased “linearly and average internode length increased quadratically as day temperature increased. The number of lateral shoots decreased quadratically as average temperature increased, and the average length of each shoot decreased quadratically as day temperature increased.
M.P. Kaczperski, W. H. Carlson and M.G. Karlsson
E.A. Baldwin, M.O. Nisperos-Carriedo and M.G. Moshonas
Tomato (Lycopersicon esculentum Mill.) fruit, cvs. Sunny and Solar Set, were analyzed at five ripening stages for ethylene and CO2 production. Homogenates from the same fruit were prepared for determination of color, flavor volatiles, sugars, and organic acids. Changes in the levels of these compounds were compared to the pattern of climacteric ethylene production. Of the flavor volatiles measured, only eugenol decreased during ripening in both cultivars and 1-penten-3-one in `Sunny' tomatoes. Ethanol and trans-2-trans- 4-decadienal levels showed no change or fluctuated as the fruit ripened while all other volatiles measured (cis- 3-hexenol, acetaldehyde, cis- 3-hexenal, trans-2- hexenal, hexenal acetone, 6-methyl-5 -hepten-2-one, geranylacetone, and 2-isobutylthiazole) increased in concentration, peaking in the turning, pink, or red stage of maturity. Synthesis of some volatile compounds occurred simultaneously with that of climacteric ethylene, CO2 and lycopene production. `Solar Set' fruit exhibited higher levels than `Sunny' of all flavor components except ethanol and hexanal in the red stage. There were no differences in organic acid levels between the cultivars; however, `Solar Set' had higher levels of sugars. Changes in acid and sugar levels showed no temporal relationship to climacteric ethylene or CO2 production.
M.G. DeWald, G.A. Moore and W.B. Sherman
Genetically characterized isozyme loci are useful for taxonomic studies. In an initial study a few Ananas genotypes were used to determine which enzyme systems would give well-resolved banding patterns on starch gels. The enzyme-staining systems that resulted in well-resolved banding patterns were used to survey more Ananas genotypes to identify and characterize isozyme polymorphism. Genetic studies were performed using seedling populations to determine the basis of variability observed among genotypes. Two peroxidase loci and three phosphoglucomutase loci were identified and characterized. Information from these studies, was used to formulate a system by which species and plant introductions could be identified and distinguished.
Farah MG Héraux, Steven G. Hallett, K.G. Ragothama and Stephen C. Weller
Trichoderma virens (Gliocladium virens) (Miller et al.) von Arx is a soilborne fungus with a high degree of rhizosphere competence that produces a potent herbicidal compound, viridiol, and therefore has potential for development as a bioherbicide. We investigated the possibility of using composted chicken manure (CCM) as a medium for the production and deployment of T. virens. We chose CCM since the safe disposal of chicken manure presents significant logistic problems, and composted manures, as well as serving as an organic source of nitrogen, have been shown to support the activity of other biological control agents. Composted chicken manure supported the growth of T. virens and the rapid production of high concentrations of viridiol, but only when it was supplemented with large quantities of nutrients, including sucrose (16% w/w). Viridiol was not stable when stored in CCM, with a rapid decline in viridiol concentrations observed in T. virens-inoculated CCM cultures. Clearly, a cheaper alternative to sucrose is required as a carbon source for T. virens in CCM or similar media, and effective storage methods would need to be found for a T. virens-based bioherbicide product. Importantly, CCM did not need to be sterilized to support the growth of T. virens and its concomitant production of viridiol, suggesting that on-farm production systems may be feasible. Trichoderma virens-colonized CCM reduced the emergence and seedling growth of redroot pigweed (Amaranthus retroflexus L.) in a greenhouse experiment and dramatically reduced the emergence of a mixed community of broadleaf weeds in the field.
Huixia Li, Zhujun Chen, Ting Zhou, Yan Liu, Sajjad Raza and Jianbin Zhou
synthesis, and chlorophyll formation ( Davies and Winsor, 2010 ; Li et al., 2001 ). Mg deficiency is common in acidic soil, particularly in highly leached humus acid soil or sandy soil with a heavy dressing of lime ( Cakmak and Yazici, 2010 ; Gransee and
Neo Edwin Nyakane, Moosa Mahmood Sedibe and Elisha Markus
, Ca and Mg play the most important roles in improving the quantitative and qualitative agronomic attributes of crops grown in greenhouses or under field conditions. Calcium plays an important role in the physiological development of plants influencing
H.T. Kraus, S.L. Warren, G.J. Bjorkquist, A.W. Lowder, C.M. Tchir and K.N. Walton
. Mineral nutrient recommendations for woody, perennial plant production include daily applications of 50 to 100 mg·L −1 N, 10 to 20 mg·L −1 P, and 25 to 50 mg·L −1 K in a 5:1:3 N:P:K ratio ( Wright and Niemiera, 1987 ). Schnelle and White (2004
Brian A. Krug, Brian E. Whipker and Ingram McCall
(excluding the pot) would be considered commercially acceptable ( Barrett et al., 1995 ). Paclobutrazol (Bonzi; Syngenta, Greensboro, N.C.) substrate drench recommendations vary from 8 mg·L −1 ( Dole and Wilkins, 2005 ), 0.5 to 1 mg/pot a.i. ( Barrett et al
Christopher J. Currey, Nicholas J. Flax and Kellie J. Walters
surface and weight of flats, flats were irrigated until leaching was visible to reduce any excess salts. Plants were irrigated alternating between tap water and water supplemented with a blend of water-soluble fertilizers [50 and 100 mg·L −1 N provided
Stephanie E. Burnett, Donglin Zhang, Lois B. Stack and Zhongqi He
. Previous research indicated that container-grown fan flowers have fewer and shorter stems, reduced leaf area, and fewer flowers when grown in substrates fertilized with more than 43.5 mg·L −1 P of ( Zhang et al., 2004 ). Phosphorus toxicity symptoms