Cider gum (Eucalyptus gunnii Hook. F.), Monterey pine (Pinus radiata D. Don), and camphor tree [Cinnamonium camphora (L.) J. Presl] were evaluated in a field study comparing the effects of herbicides on tree growth. Trees were planted on 13 May 1983 and treated on 20 May 1983, 10 Apr. 1984, and 4 Oct. 1984 with simazine, oryzalin, napropamide, and oxyfluorfen. Glyphosate was applied as a postemergence treatment in all basins on 20 Mar. 1984. None of the herbicides injured the trees. Trunk circumferencesin treated plots increased as much as 553% over untreated plots. All species showed a positive response to increasing weed control. Chemical names used: 6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine (simazine); 3,5-dinitro-N4,N4-dipropylsulfanilamide (oryzalin); N,N-diethyl-2-(1-naphthalenyloxy)-propanamide (napropamide); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); N-(phosphonomethyl)glycine (glyphosate).
Pitch canker, caused by Fusarium subglutinans f. sp. pini, causes branch dieback and stem cankers in many species of pine. Monterey pine (Pinus radiata D. Don), one of the most widely planted pines in the world, is extremely susceptible to pitch canker. Four other pine species, which might serve as alternatives to Monterey pine in landscape settings, were found to be relatively resistant, based on the size of lesions resulting from branch inoculations under greenhouse conditions. Of these species, Japanese black pine (P. thunbergiana Franco) was the most resistant, followed by Canary Island pine (P. canariensis Sweet ex K. Spreng), Italian stone pine (P. pinea L.), and Aleppo pine (P. halepensis Mill.). Consistent with these findings, a field survey conducted in Alameda County, Calif., revealed Monterey pine to have the highest incidence of infection, with significantly lower levels in Aleppo, Canary Island, and Italian stone pines. Japanese black pine was not observed in the survey area.
Morphactins, mixed with non-phytotoxic paraffinic, low molecular weight oil, were applied as bark bands and tested for growth inhibition of trees growing under field conditions. Three species were tested: Monterey pine (Pinus radiata D. Don.), olive (Olea europaea L. cv. Manzanillo) and eucalyptus (Eucalyptus globulus Labill). Shoot elongation was inhibited in all three species, but sensitivity to the treatment varied.
Rooting of stem cuttings of Bougainvillea cv. San Diego Red, Ceratonia siliqua L., Chrysanthemum morifolium Ramat. cvs. Golden Anne and Mandalay, Euonymus japonica L. cv. Yellow Edge, Euphorbia pulcherrima Willd. cv. Eckspoint C-1 Red, Hedera helix L., Trachelospermum jasminoides [Lindl.] Lem., Juglans hindsii (Jeps.) Jeps., Pistacia chinensis Bunge, and Salix laevigata Bebb. is greatly promoted by basal dipping in H2SO4 prior to applying indolebutryic acid. Pre-treatment with NaOH results in considerable increase of rooting of cuttings of Rhododendron (Pericat) cv. Sweetheart Supreme, Bougainvillea, Liquidambar styraciflua L., Osmanthus heterophyllus G. Don cv. Ilicifolius, and Pinus radiata D. Don.
A new formulation of maleic hydrazide (Royal Slo-Gro), containing the surfactant polyoxyethylene trimethylnonyl ether (TMN-10), was superior to the maleic hydrazide formulation, containing polyoxyethylene nonyl surfactant (X-77) for inhibiting shoot elongation of Pinus radiata L., Xylosma congestum (Lour.) Merr., Viburnum japonicum (Thunb.) Spreng., and Coprosma repens A. Rich. The X-77 formulation was superior to the one containing TMN-10 for inhibiting growth of Juniperus sabina L. ‘Tamariscifolia’, Pyracantha coccinea (Roem.), and Callistemon citrinus (Curt.). There was little difference between the two formulations in tests with Cotoneaster pannosa (Franch.) and mixed results were obtained with Nerium oleander L. The greatest advantage of the TMN-10 formulation was manifested in Pinus where inhibition occurred without severe foliar discoloration, necrosis, or tip dieback which are characteristic of other maleic hydrazide formulations.
Pitch canker, caused by Fusarium subglutinans f. sp. pini, causes branch die-back and stem cankers in many species of pine. Monterey pine (Pinus radiata D. Don), one of the most widely planted pines in the world, is extremely susceptible to pitch canker. Four other pine species, which might serve as alternatives to Monterey pine in landscape settings, were found to be relatively resistant, based on the size of lesions resulting from branch inoculations under greenhouse conditions. Of these species, Japanese black pine (P. thunbergiana Franco) was the most resistant, followed by Canary Island pine (P. canariensis Sweet ex K. Spreng), Italian stone pine (P. pinea L.), and Aleppo pine (P. halepensis Mill.). Consistent with these findings, a field survey conducted in Alameda County, Calif., revealed Monterey pine to have the highest incidence of infection, with significantly lower levels in Aleppo, Canary Island, and Italian stone pines. Japanese black pine was not observed in the survey area.
When the slow-release fertilizers Nutricote 13N–5.7P–9.1K (4–5 month) (N1), Nutricote 13N–5.7P–9.1K (8–9 month)(N2), Osmocote 15N–5.2P–12.5K (3–4 month)(01), Osmocote 18N–4.8P–8.3K (8–9 month) (02) and Osmocote Plus 15.4N–4.8P–10.8K (3–4 month)(03) were incorporated into Pinus radiata D. Don bark at a rate of 2 g·liter–1, S equivalent to about 8%, 0.6%, 17%, 16%, and 20%, respectively, of their S contents appeared in leachates over 64 days. Phlox drummondii Hook. ‘Candy’ were grown in a soilless potting mix containing N1, O1, or O3 at 3, 6, and 9 g·liter–1 alone or supplemented with gypsum and/or a dilute S-free liquid fertilizer. At 3 g·liter–1 addition, plants in N1 pots grew better with gypsum and liquid feed added separately and much better when both were applied. At 6 and 9 g·liter–1, neither gypsum nor liquid fertilizer increased shoot weights, but plants grown without gypsum were chlorotic, which was attributed to S deficiency. The combined addition of gypsum and liquid fertilizer to pots containing N1 at 6 and 9 g·liter–1 gave significantly larger shoot weights.
Greenhouse tomato (Lycopersicum esculentum Mill.) producers are urged to reduce their environmental footprint. Here, the suitability of biochar produced from tomato crop green waste as a substrate for soilless, hydroponic tomato production was evaluated. Substrates containing different combinations of biochar (BC) and pine (Pinus radiata D. Don) sawdust (SD) were produced (BC0-SD100, BC25-SD75, BC50-SD50, BC75-SD25, and BC100-SD0) and characterized. The effect of these substrates on tomato growth, yield, and fruit quality was studied. Most of the measured properties of substrates containing biochar were suited to use as a soilless substrate. The electrical conductivity (EC) of substrates containing biochar was initially high (>4.6 mS·cm−1), but was easily reduced to <0.5 mS·cm−1 by rinsing with water before use. The pH of substrates containing biochar was higher than is considered acceptable for tomato production (7.5–9.3) but did not significantly (P < 0.05) affect any plant growth, yield, and fruit quality indicators measured compared with those of plants grown in pine sawdust. The results support the concept of creating a closed loop system whereby biochar produced from tomato crop green waste is used as a substrate for soilless, hydroponic tomato production, providing a sustainable means to support the growth of high-value food crops.
Root pruning and care during the first two nursery transplantings of 4 tree species significantly increased the percentage of plants with good root systems. The 4 species were Eucalyptus sideroxylon A. Cunn., red iron bark; Pinus radiata D. Don., Monterey pine; Pistacia chinensis Bunge., Chinese pistache; and Quercus ilex L., holly oak. The percentage of trees with good root systems decreased the longer seedlings stayed in the seed flat and in peat pot liners, particularly those not root pruned. In all but one case, the earlier plants were moved from the seed flat into peat pots and on into into gallon cans, the more the plants grew in caliper and height.
Plants root pruned during the early moves were larger than those not root pruned. However, root pruning at the later moves resulted in smaller plants than those moved earlier or than those moved at the same time but not root pruned. The combination of lengths of time in the seed flat and in the peat pot (time in the greenhouse) which resulted in the best combination of quality root systems and large plants was only 1/2 to 2/3 the time now common nursery practice (90-120 days).
), and Abies Mill. ( Benson et al., 1998 ; Hinseley et al., 2000 ). Even cultivars, clones, or provenances of the same species have shown significant differences in susceptibility, as in the case of Pinus radiata D.Don ( Butcher et al., 1984